Stabilizer for lifting carriage of a lift truck



Jan. 17, 1956 B. 1. ULINSKI 2,731,154

STABILIZER FOR LIFTING CARRIAGE OF A LlFT TRUCK 2 Sheets-Sheet 1 Filed April 6, 1955 WWW,

YIIHH II INVENTOR K LL///;/ wk,

BY fl /waa 1 ATTORN EY Jan. 17 1956 s. l. ULINSKE 2,731,164

STABILIZER FOR LIFTING CARRIAGE OF A LIFT TRUCK Filed April 6, 1953 2 Sheets-Sheet 2 INVENTOR f Q/A/J 6, BY

ATTORNEY STABILIZER FOR LIFTING CARRIAGE OF A LIFT TRUCK Bronislaus I. Ulinski, Chicago, Ill., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn, a corporation of Connecticut Application April 6, 1953, Serial No. 346,955

Claims. (Cl. 214736) This invention relates to lift trucks of the class having uprights upon which a load carriage is mounted for vertical movement. In trucks of this class, when the carriage supports a load in laterally offset relation to the up rights, the carriage has a tendency to cock relatively to the uprights and thereby to bend the uprights. It is the purpose of my invention to reduce the stresses that occur in the uprights due to offset loading of the carriage.

As a very important feature of my invention, I enable the uprights to oppose cocking movement of the load carriage through forces that are applied in a lengthwise direction relatively to the uprights. The uprights are thereby stressed to a much lesser degree than when the cocking action of the carriage is permitted to have a lateral bending efiect upon the uprights. More particularly, I lock each of the uprights to the load carriage so that the opposed sides of the carriage can not move upwardly or downwardly relatively to each other.

As a detailed feature of my invention, I utilize rack and pinion means for locking the uprights relatively to the load carriage. I prefer to mount a pair of pinions to rotate integrally with one another upon the carriage, with each pinion meshing with a rack fixed upon one of the uprights. The pinions thereby rotate as the carriage moves vertically on the uprights, and the vertical movement of the carriage must be simultaneous with regard to both uprights.

I have thus outlined rather broadly the important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter, and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims he regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings:

Fig. l is a side view showing a preferred form of my invention embodied in a truck.

Fig. 2 is a plan view showing my invention.

Fig. 3 is a front view of parts shown in Fig. 2.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2.

For the purpose of describing my invention, I show in the drawings an industrial truck T of a usual type having a pair of uprights upon its front end, with a load carriage 11 mounted for vertical movement on these uprights. In the particular example shown, the mounting means for the carriage 11 includes vertical members 12 on the carriage that carry rollers 13 on stub shafts 14, the uprights 10 being formed actually as channel members in which the rollers 13 run. Also, 1 have shown in Figs. 1 and 2 primary uprights 15 through which the uprights 10 are mounted for vertical movement on the truck T, this being an arrangement that is quite customary in the prior art. These details are shown only by way of example and are not essential to an understanding of my invention, it being necessary to know merely that the truck has a pair of uprights 10 and a load carriage 11 mounted to move vertically on these uprights.

To understand my invention to the fullest extent, it is necessary to appreciate the very considerable tendency of the load carrier 11 to cock relatively to the uprights 10 when supporting a load in laterally offset relation to the pair of uprights. To illustrate this cocking action, I have shown carried by the carriage 11 a boom 16 that can swing on a vertical pivot 17 to the position of Figs. 2 and 3 for supporting a load in oliset relation to the truck T. The load on the boom 16 tends to rotate or cock the carriage 11 relatively to the uprights 10. This imposes a bending load on the uprights 10, as will be quite ob worm.

in my extremely novel construction, I resist the cocking tendency of the carriage 11 by forces applied to the uprights 10 in a vertical direction merely by locking each side of the carriage to the uprights. This is accomplished preferably through a pair of pinions 18, 19 rotating together on the carriage 11 and engaging racks on the uprights. In the preferred form of my invention, the pinions 18, 19 are secured to the ends of a horizontal shaft 26 that rotates in brackets 21 on the carriage 11. pinions 18, 19 each coact with one of the uprights 10 through a vertical rack 22, these racks being shown in Fig. 2 as members welded to the sides of the uprights 10.

Because the pinions 18, 19 must rotate together, it will be understood that the load carriage 11 is locked to each upright so as to prevent vertical movement of one side of the carriage relatively to the other side. I thereby prevent cocking of the carriage 11 relatively to the uprights 10, and I very considerably reduce the stresses that occur in the uprights 10. More particularly, the pinions 18, 19 enable the uprights 10 to oppose the cocking tendency of the carriage 11 through forces acting lengthwise of the uprights, with these forces stressing the uprights 10 to a lesser degree than would forces tending to bend the uprights. In addition, the racks and pinions contribute this locking action automatically in all positions of carriage 11 relatively to the uprights 10.

I believe that the extremely novel features of my invention will now be understood, and that the very considerable merit of the invention will be fully appreciated by those skilled in the art.

I new claim:

1. in a lift truck of the class described, a pair of channel uprights, a load carriage at the front of said channel uprights, each opposed side of the carriage arranged relatively to a corresponding channel upright, upper and lower rollers on each side of said load carriage engaged in the channel of the corresponding upright in vertically aligned relation to mount the carriage for vertical movement relatively to the uprights, said uprights acting through said rollers to hold the carriage against tilting relatively to the uprights in a fore-and-aft direction, said carriage when supporting a load in a position offset transversely relatively to the pair of uprights tending to move the rollers transversely out of alignment with said uprights whereby to cock or wedge relatively to said uprights, a rack on each upright coextending linearly therewith, a pair of pinions, means mounting said pair of pinions on the load carriage to rotate in meshed relation to both racks as the carriage moves vertically on said uprights, and means connecting said pinions for rotation integrally with each other to hold the carriage with its The.

rollers in vertically aligned'relation to the uprights whereby to prevent the application of transverse bending stresses to the uprights when .the carriage supports a load in transversely ofiset relation to the uprights.

"2. In a lift truck of the class-described, a load carriage, a pair of uprights, each opposed side of "the carriage arranged relatively to -a-correspond-ing one of said uprights, an upper member and a lower member on each side of said lead carriage engaged with the corresponding upright to mount the carriage for vertical movement relatively to the uprights and holding the carriage against tilting in a fore-and-aft direction relatively to the uprights, said upper and Llower'rnembers tending to move transversely out of vertical alignment with said uprights when the carriage supports a load in a position offset transversely relatively to the :pair of uprights whereby to cook or wedge relatively to the uprights, a rack on each upright coextendin'g linearly therewith, apair of'pinions, means mounting said pair 'of pinions on the load carriage to rotate in meshed relation to both racks as the carriage moves verticallyon said uprights, and means connecting said pinions for rotation integrally with each other to hold the carriage with :its upper and lower members in vertically aligned relation to the uprights whereby to prevent the application of transverse bending stresses to the uprights when t the carriage-supports a load in transversely offset relation tot'he uprights.

3. In a lift truck of the class described, a load carriage, a pair of uprights, each opposed side of the carriage arranged relatively to a corresponding one of said uprights, 3-

an upper member and a lower member acting between each side of the carriage and the corresponding upright whereby to'mount said load carriage at the front of said uprights for vertical movement relatively thereto, said uprights accepting from said upper and lower members forces tending to bend the uprights in a forward direction whereby 'to prevent forward tilting 'of the load carriage, said upper and lower members tending to cock or wedge relatively to said uprights whereby to bend the uprights in atransverse direction'throug'h movement out of alignment with said uprights when the carriage supports a load in transversely offset relation to said pair .of uprights, and means elfective in all vertical positions of the load carria'ge on the uprights for locking the opposed sides of the carriage to both uprights to hold the carriage with its said'upper and lower members in alignment with the uprights whereby to prevent the application of transverselbending stresses to said uprights.

4. In a'lift truck of the class described, a pair ,of uprights, a load carriage, veach opposed side of the carriage arranged relatively to a corresponding one of said uprights, an upper and a lower member on each side of said load carriage coacting with the corresponding upright to mount the carriage at the front of said uprights for vertical movement relatively thereto, said upper and lower members tending to bend the uprights in a forward direction while holding the carriage against forward tilting relatively to the uprights, said carriage when supporting a load in transversely oifset relation to said pair of uprights tending {to cock or wedge relatively to the uprights through movement downwardly atone side relatively to one upright and upwardly at the other side relatively to the other upright whereby to bend the uprights in a transverse direction, and means acting between the carriage and each upright to cause the movements of the carriage to be equal relatively to each upright whereby to prevent the application of transverse bending stresses to the uprights.

5. in a lift truck of the class described, a pair of uprights, a load carriage, each opposed side of the carriage arranged relatively to a corresponding one of said uprights, air-upper and a lower memberon each side of said load carriage coacting with the corresponding upright to mount the carriage at 'the front of said uprights for vertical movement relatively thereto, said upper and lower members tending to bend the uprights in-a forward direction while holding the -carriage against forward tilting relatively to the uprights, said carriage when supporting a load in transversely offset relation to said pair of uprightstending to bend the uprights in a transverse direction through movement downwardly at'oneside relatively to one upright and upwardly at the other'side relatively to the other upright, a rack on each upright coextending linearly therewith, apair of pinions, means mou'ntingsaid pair of pinions on the opposed sides of the load carriage to rotate in meshed relation to both racks as the carriage moves vertically on the uprights, and means connecting the pinions for rotation integrally with each other and causing the movement of the carriage to be equal relatively to each upright whereby-to prevent the application of transverse bending stresses to the uprights.

References Cited =in the :file of this patent UNITED STATES PATENTS 1,469,689 Prius Oct. ,2, 1923 1,837,486 Remde :Dec. 22, .1931 1,920,243 Casper Aug. 1, 1933 2,410,373 Wcstervelt, Ir. Oct. 29., 1946 2,517,085 Cirillo ,Aug. ,1, 195.0 2,528,401 Ulinski Oct, 31, 1950 2,593,630 Thompson Apr. 22, 1952 2,621,821 Melin Dec. 16, 1952 

